LIFE HISTORIES OF NORTH AMERICAN DIVING BIRDS. 41 



rushes. Sometimes they are well concealed in thick clumps of reeds, 

 but usually they can be easily seen, although not so conspicuous as 

 those of the horned or eared grebes. The nests are generally scat- 

 tered and only a few pairs of birds were found in each slough. When 

 located in deep water the nest is. strictly a floating affair, but otherwise 

 it is more often partially connected with the bottom. A large amount 

 of material is collected and piled up into bulky mass, mostly below 

 the surface of the water, often large enough to fill a bushel basket; 

 on top of this, above the water, a smaller and neater nest is built. 

 The material consists of whatever the bird can conveniently find ii^ 

 the vicinity in the way of decayed vegetable matter, dead reeds, flags, 

 rushes, or grasses ; sometimes fresh, green flags are mixed in with the 

 rubbish and often the whole structure is plastered together with a 

 quantity of the soft, green vegetable scum which grows in stagnant 

 water. This wet and slimy structure is built up but a few inches 

 above the water, usually from 2 to 4 inches, and measures about a 

 foot in diameter ; the nest cavity is but slightly hollowed and the eggs 

 are partially buried in the soft material. 



Eggs. — The pied-billed grebe lays from 3 to 10 eggs, but the ex- 

 tremes are rare and the set usually consists of from 5 to 7 eggs. In 

 shape the eggs are " elliptical ovate " or " elliptical oval," sometimes 

 almost " fusiform." The shell is generally smooth, Avith a slight lus- 

 ter, but sometimes dotted with small excrescences or lumps. The color 

 of the clean, freshly laid o.^^ is dull bluish white or pale olive white, 

 but it soon becomes stained or clouded with various buffy shades ; some 

 sets are uniformly stained as dark as " wood-brown " or " Isabella 

 color;" generally more or less mud and bits of nesting material sticks 

 to the <^gg^ giving it a mottled appearance. The measurements of 48 

 eggs in the United States National Museum collection average 43.4 by 

 30 millimeters ; the eggs showing the four extremes measure 47 by 30, 

 44 by 33, 39 by 29.5, and 44 by 28 millimeters. 



Mr. C. H. Pease made some interesting observations on the nesting 

 operations of this species at Canaan, Connecticut, during May and 

 June, 1913. He sent the results of his observations to Dr. Louis B. 

 Bishop, who has given them to me. On May 22 he found the nest 

 completed and the first egg laid ; on May 28 the eighth and last <6g^ 

 was laid, one having been laid each day. The first two eggs hatched 

 on June 15, one in the forenoon and one in the afternoon; and the 

 last ^gg hatched at 9.15 in the morning of June 21 ; the record shows 

 that the period of incubation, in this case, was from 23 to 24 days. On 

 June 22, the day after the last ^g'g hatched, only one young bird was 

 left in the nest. On July 3 he saw the whole family of eight, " half 

 grown in less than two weeks." 



Both sexes incubate. So far as I know, only one brood is raised in a 

 season ; but there are some very early and very late dates for nesting 



